As mentioned, the radarscope clock shows 0906:14 GMT at the time of frame 771, or 0406 local time. However, a transcript of the radio transmissions between RAPCON and the aircraft commander is at variance with this, indicating that the B-52 lost its UHF transmitters at 0358 local time, simultaneous with the first appearance of the radar target. Compounding this, the investigating officer's timetable of events linked to the B-52 flight track has the aircraft some 16 miles NW of Minot at 0406 by the clock; yet the transcript of the pilot's communications with RAPCON would place the B-52 some miles SE of Minot by 0406 and perhaps already turning back on a NNW heading after executing its missed approach.
These inconsistencies at first sight suggest a possible 7-8 minute systematic error in the times recorded either in the RAPCON transcript or by the radarscope clock. The photographed clock may seem the more reliable record of the two, given that there is evidence that RAPCON transcript is at least incomplete. However clock error cannot be ruled out, since the clock is a mechanical timer which is required to be re-set by hand prior to each mission. Setting the clock accurately (to GMT) was a checklist item, but according to former B-52 navigator Richard Sessler it was nevertheless "easy to forget" and he admits to doing so himself on occasion.
The possibility that the clock may run inaccurately has been considered. An inquiry by Jim Klotz to the manufacturing company, Bulova, disclosed that typical variation acceptable in a comparable instrument watch might have been in the region of +/- 1/2 minute over 3 days, and that a variation of 7-8 minutes in 10 hours (the duration of the mission) would indicate a mechanism in bad need of an overhaul. Although this has to be considered less likely than a setting error, as mentioned above the photos do indicate a small discrepancy between a scan/photo rate of 3 seconds and the clock time of around 0.5 - 1.0 second over 36 seconds which, multiplied out over 10 hours, would accumulate to approximately 8 minutes. In other words the clock is "slow" relative to the nominal 20 RPM radar scan rate, which, if the latter could be relied upon, might be explained by inadequate winding or a weak spring, for example.
However the discrepancy from the indicated Control Tower time is in the other direction, and would require the clock to be fast, not slow. So this phantom 8 mins appears to be a coincidence. The small photo discrepancy is probably due to imprecision in the radar antenna's hydraulic motor and/or rotation control mechanism (the ASB-4/9 Tech Order gives the nominal 20 RPM setting as "17.5 - 22.5 RPM") and there is no internal evidence in the photos that the clock is not accurate.